public string GetTime(DateTime dt)
{
Int64 retval = 0;
DateTime st = new DateTime(1970, 1, 1);
TimeSpan t = (dt.ToUniversalTime() - st);
retval = (Int64)(t.TotalMilliseconds + 0.5);
return retval.ToString();
}

javascript 的dateObj.getTime() 在为C#的获取方式